/Engine/Source/Runtime/Experimental/Chaos/Public/GeometryCollection/GeometryCollectionClusteringUtility.h
Cluster all existing bones under a new root node, so there is now only one root node and a completely flat hierarchy underneath it
static void ClusterAllBonesUnderNewRoot ( [FGeometryCollection](API\Runtime\Chaos\GeometryCollection\FGeometryCollection) * GeometryCollection )